Measuring pump



May 2, 1957 R. F. SCHNELLE-:R 3,316,853

MEASURING PUMP Filed April 4, 196e 2 Sheets-sheet 1 uw m un nu (n MEM May 2, 1967 R. F. SCHNELLER MEASURING PUMP Filed April 4, 1966 2 Sheets-Sheet 2 All: M Ar.. ..I.\\n. l

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United States Patent() 3,316,853 MEASURING PUMP Rudy F. Schneller, OFallon, Mo., assignor to McNeil Corporation, Akron, Ohio, a corporation of Ohio Filed Apr. 4, 1966, Ser. No. 539,789 10 Claims. (Cl. 103-203) Among the several objects of the invention may be noted the provision of a manually operated pump for liquids which is operative only when a volume of liquid of predetermined measure can be discharged by the pump; the provision of a pump for liquids which is made inoperative by the presence of any substantial amount of gas in the liquid being pumped, and the provision of such a pump wherein such gas may be manually vented from the pump without being discharged through the normal liquid outlet. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the construction hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

FIG. l is an axial section through a measuring pump made according to the invention, showing the pump parts at the end of a discharge stroke and at the beginning of a recharging stroke;

FIG. 2 is a cross section similar to FIG. 1 showing the pump parts at the end of a charging stroke and at the beginning of a `discharging stroke;

FIG. 3 is a cross section similar to FIGS. 1 and 2 show ing the pump parts after initial movement during a discharging stroke; and

FIG. 4 is a cross section taken along line 4--4 of FIG. 2.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. For clarity the lubricant or liquid which the device pumps is not shown but it will be understood that the device when in operation is properly inilled.

Referring now to the drawings in detail, a pump of this invention comprises a cylinder 1 formed in a pump body 3. Lubricant is delivered to cylinder 1 through a valved inlet passage 5 and a port 7 at the bottom of the cylinder. Lubricant is discharged from the cylinder through port 7 and a valved discharge or outlet passage 9. Port 7 is formed in the pump body. The outlet passage 9 is in a member 13 held on a nipple 11 threaded into the pump body. The holding means is a sleeve 15 threaded on the nipple 11, packing 8 being located between the members 13 and 11.

A ball 17 in a passage 10 in nipple 11 is biased against an annular seat 19. The bias is provided by a spring 21 reacting from the ymember 13. Thus ball 17 is outwardly openable and inwardly closable in passage 10. `Inlet passage 5 is normally closed by a ball 23 which is biased against an annular seat 25 in passage 5 by a spring 27 reacting from a shoulder in the nipple 11.

Inlet passage 5, outlet passage 9 and port 7 communicate with each other through a chamber 29. During a charging stroke of the pump lubricant from passage 5 passes around ball 23 and then through chamber 29 and port 7 into the cylinder 1. Spring 21 holds ball 17 seated against the pressure of lubricant in chamber 29 during a cylinder-charging stroke. During a discharging stroke lubricant from cylinder 1 leaves the cylinder through port 7, chamber 29, and through passages and 9. A slot 31 in the right end of nipple 11 permits free flow of lubricant through chamber 29 into the nipple.

Lubricant or other liquid lis delivered to the pump from a lubricant supply barrel or cartridge 33. An open left end of the barrel is threaded into a boss 35 of the pump body and is sealed by a washer 3.7.

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The barrel 33 contains a suitable liquid lubricant such as grease, in a space designated 39. This lubricant is moved toward inlet passage 5 by a follower piston 41. Piston 41 travels along a rod 43 and is biased from rightto-left by a spring 45 reacting from a head 41 on the right end of the barrel. Force applied to piston 41 may alternatively be provided by other means, such as by introducing a gas under pressure `into the right end of the barrel behind the follower piston 4l, as will be understood by those skilled in the art.

A piston 49 is positioned in the pump body and is adapted to sweep through cylinder 1 between a lowered position (FIG. l) wherein the piston lower end S1 is spaced slightly above the lower end of cylinder 1, and an Lipper position (FIG. 2) wherein the piston lower end 51 is at the top of cylinder 1. When the piston reaches its FIG. 2 position a shoulder 53 formed by a step on the upper end of the piston engages a shoulder 55 formed by a radially inwardly projecting flange on a nipple 57 threaded at the top of the pump body. Engagement between shoulders 53 and 55 limits upward movement of the piston.

Piston 49 has a stepped cylindrical bore S9 which slidably receives the lower end portion of a plunger 61. The sliding connection vbetween the plunger and the bore of the piston is sealed by an O-ring 63 seated in a groove in the plunger. A plug 65 threaded into the lower end of the plunger has a head which is larger in diameter than the adjacent portions of the plunger. This head is engageable with a shoulder 67 near the lower end of the piston to limit upward lost-motion travel of the plunger relative to the piston. Downward `movement of the plunger rela- 59 in the piston. Plug 65 and shoulders` 67, 69 and 71 permit limited lost-motion travel of the plunger relative to the piston. The extent of this lost-motion travel is shown by comparing the relative positions of the plunger and piston in FIGS. 2 and 3.

The plunger and piston are moved through a charging and discharging stroke by a linkage connected to the plunger and to the body of the pump. This linkage comprises an operating handle 73 pinned at 75 to the upper end of the plunger 61. One end of handle 73 is connected by a pivot pin 77 to the bifureated end of a rocker arm 79. The other end of the rocker arm is pivoted at 81 to the pump body. When the handle is in its FIG. 2 position the plug 65 is in contact with shoulder 67 and shoulders 53 and 55 are in engagement. Clockwise movement of the handle is limited by engagement of the plug 65 of the plunger with the Abody 3 at the lower end of the cylinder as shown in FIG. l. A latch pin 83 reciprocates in a hollow latch pin mounting member 85 threaded into a lateral opening 87 in the pump body. The latch pin is biased toward the position shown in FIGS. 2 and 3 by a spring 89 which reacts from a shoulder 91 in the mounting member 85 against a shoulder 93 of the latch pin. Movement of the latch pin to the right as viewed in the drawings is limited by engigement of a knob 95 on the left end of the latch pin with the left end of the mounting member 35 (FIGS. 2 and 3).

At the right end of pin 83 is a bore 97 openingtb cylinder 1 and communicating through lateral passages 99 with an annular passage 191. When. the pump is primed, the bore 97 and passages 99 and 101 are filled with lubricant or other liquid being pumped. If the lubricant is under pressure, this will act on the pin against the biasing force of spring 39. When the force exerted on the pin 83 from cylinder 1 exceeds the force of spring 89 the latch pin moves to the left to its FIG. 1 retracted position. In the absence of such pressure the right end 3 of the latch -pin projects into cylinder 1 to block downward movement of piston 49 (FIG. 3).

FIG. 4 of the drawings illustrates means for purging cylinder 1 of air or other gases that may be contained in lubricant delivered to the cylinder. This includes a bleed passage 103 communicating with cylinder 1 thlough the pump body. A plug 105 has a tapered end 107 engageable with a seat 109 around the left end of the passage 103. When plug 105 is backed away from seat 109 the passage 103 is placed in communication with a branch passage 111 leading to the atmosphere. This permits air and liquid from cylinder 1 to be discharged from the pump through passages 103 and 111. Normally the tapered end 107 of the plug is in engagement with seat 109 to close communication between passages 103 and 111.

Operation is as follows:

Assume initially that the barrel 33 is charged with a sufficient amount of lubricant in space 39 to provide one or more complete charges of lubricant to the pump cylinder 1. Also assume that the inlet passage 5, outlet passage 9, port 7, chamber 29, and the bores and passages in the retaining pin 83 are filled, i.e., primed with lubricant.

In order to charge cylinder 1 with lubricant the pump parts are moved from the FIG. 1 to the FIG. 2 position. This is accomplished by lifting upwardly on the right end of handle 73 until the shoulder 53 on the upper end of piston 49 engages shoulder 55 near the top of the pump body. During initial upward movement of plunger 61 it slides through the lpiston from the position shown in FIG. l wherein the plunger projects beneath the lower end 51 of the piston to a position wherein the head of plug 65 engages shoulder 67 on the piston, Then further upward movement of the plunger by lifting upwardly on the right end of handle 73 raises the piston and plunger together until they reach the FIG. 2 stop position wherein piston shoulder 53 contacts shoulder 55 to stop the piston and plunger. As the piston 49 clears the end of blocking pin 83, spring 89 biases the pin to the FIG. 2 position wherein its right end projects into cylinder 1 and blocks downward movement of the piston. As the piston and plunger are elevated from the FIG. l to the FIG. 2 positions the suction created by movement of these parts together with the pressure exerted Iby lubricant in the space 39 in the barrel unseats ball 23 and permits lubricant to flow through the inlet passage 5, upwardly through port 7 and into cylinder 1 to charge the cylinder with lubricant.

If the cylinder is free of entrained gas then lubricant in cylinder 1 can be discharged through its outlet passage 9 by moving the handle 73 clockwise. the plunger first moves through the piston from its FIG. 2 to its FIG. 3 position wherein shoulder 69 of the plunger engages shoulder 71 `of the piston. Because cylinder 1 is full of liquid and substantially free of entrained gas, this initial downward movement of the plunger into the cylinder rapidly builds up fluid pressure in the cylinder. This acts on the pin 83, thereby forcing the pin into the mounting member 85 against the force of spring 89. This occurs because of the substantially imcompressible nature of liquids. Ball 17 in passage 9 remains seated at this time because it takes more force to unseat the ball then to retract pin 83. Once pin S3 has been forced out of the cylinder 1, the handle 73 can be lowered from the FIG. 3 to the FIG. 1 position, thereby driving the piston and .plunger through cylinder 1 to force lubricant `out of the cylinder through the port 7. Lubricant leaving port 7 passes around ball 23, through the slot 31 in nipple 11 and unseats ball 17 so that the lubricant may flow through the outlet passage 9 to a point of lubrication (not shown). It will be understood that a hose, nozzle, etc. can lbe attached to a downstream end of the outlet passage 9'for carrying the lubricant to a point of lubrication. When handle 73 reaches its lowered FIG. 1 position spring 21 again seats ball 17 so that recharging As this occurs of the cylinder will not draw lubricant from passage 9 into the cylinder.

The construction of the pump is such that if a significant amount of air or other gas is entrained with the liquid in cylinder 1 during a charging stroke, then the piston cannot be lowered from its FIG. 2 to its FIG. 1 position. The pump is rendered inoperative under these conditions by the locking pin 83 which is not retracted unless cylinder 1 is substantially full of lubricant or other substantially incompressible liquid at the time plunger 61 moves from its FIG. 2 to its FIG. 3 position. If there is a substantial quantity of gas entrained in cylinder 1, the initial downward movement of the plunger to its FIG. 3 position will compress this gas. Its rise in pressure does not equal that which would occur in lubricant which is free of gas. Thus pin 83 will not be pushed back out of cylinder 1 and downward movement of piston 49 is blocked (FIG. 3). As a result displacement of the liquid from the cylinder cannot occur. Thus failure of pin 83 to retract from the cylinder constitutes means for indicating less than a full charge of gas-free lubricant in the cylinder and also guarantees that only a full measured volume of gas-free lubricant will be discharged from the pump.

When the operator finds he is unable to depress handle 73 past its FIG. 3 position because plunger 49 is blocked by pin 83, there are two alternative courses of action available. First he may manually retract the pin by using the knob on the left end of the pin. With the pin held retracted the handle can be moved downwardly so that liquid and gas present in cylinder 1 are discharged through the passage 9. While this method will clear cylinder 1 of gas it is unsatisfactory if a measured charge of gasfree lubricant is to be injected at the point of lubrication since less than the desired measured charge will be forced from the cylinder.

In -instances where only measured charges of gas-free lubricant are to be provided through passage 9, the plug is unscrewed to unseat its tapered end 107 from the seat 109, thereby placing the passages 103 and 111 `in communication. Then with the pin 83 manually retracted the plunger and piston are forced into the cylinder by pulling downwardly on the handle. In this manner the liquid and gas in the cylinder is forced thr-ough passages 103 and 111 to clear cylinder 1. The knob 95 is then released, the end 107 of plug 105 is seated against seat 107, and handle 73 is raised to with lubricant. If gas is delivered to cylinder 1 due to the barrel 33 being empty or substantially empty, a fresh fill of lubricant in the barrel 33 is indicated.

The pump is especially useful where a measured charge of gas-free lubricant must be delivered to a point of lubrication. By way of example, the pump may be used for lubricating ball joints lor other bearings of automobiles where the lubricating system is designed for lubrication at long mileage interv-als, such as, for example, at 36,000-mile intervals. The ball joint seals in such automobiles are designed to retain lubricant and exclude contaminants from the atmosphere but they are not made to withstand internal pressures much in excess of atmospheric pressure. Therefore it is required that a specific measured quantity of lubricant (such as 10 grams) be provided to the joint in order to avoid excessively high internal pressures which would damage or blow out the seals. At the same time, the charge delivered to the joint must be free of gas so that there will be an adequate supply of lubricant for the joint between lubrication intervals. By using a pump of the invention having the proper size of cylinder, the desired quantity of gas-free lubricant can be injected into the joint. The pump can be used for injecting the original or a replacement charge of lubricant into the bearing. It also can be used in other environments where injection of a specific measured quantity of gas-free lubricant or other fluids is required.

In view of the above, it will be seen that the several again charge the cylinder 1 objects of the invention are achieved and other advantageous results attained.

As Various changes could be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A pump for liquids comprising:

a cylinder,

a liquid inlet passage yand a liquid outlet passage communicating with the cylinder,

a first check valve closing the discharged from the cylinder,

a second check valve closing the outlet passage to the ow of liquid from the outlet passage into the cylinder,

a plunger,

means tor reciprocating the plunger throughout a full stroke,

means for limiting the stroke of the plunger,

a reciprocating piston movable through the cylinder between a lirst position wherein the cylinder is charged with liquid and a second position wherein liquid has been discharged from the cylinder, the plunger having a sliding lost-motion connection with the piston whereby the plunger is movable into the cylinder relative to the piston during the first part of a cylinder discharging stroke and movable out of the cylinder relative to the piston during the tirst part of a cylinder charging stroke, and a latch pin having an end portion movable between an extended position wherein it projects into the cylinder adjacent to the piston when the piston is in its lirst position for blocking movement of the piston into the cylinder and a retracted position wherein it is withdrawn from the cylinder to permit movement of the piston from its iirst position to its second position,

means biasing the latch pin to its extended position,

the latch pin being moved against the biasing means to its retracted position by an increase in pressure of substantially gas-free liquid in the cylinder resulting from initial movement of the plunger into the cylinder during a cylinder discharging stroke, thereby unblocking the piston so that further movement of the plunger after its initial lost-motion travel relative to the piston causes the piston and plunger simultaneously to sweep through the cylinder for discharging liquid from the cylinder through the outlet passage.

2. A pump according to claim 1 wherein the plunger slides through the piston during its lost-motion movement, and the piston forms shoulders engageable by spaced portions of the plunger to limit lost-motion movement of the plunger` relative to the piston.

3. A pump according to claim 1 wherein the means for limiting the stroke of the plunger comprises means on the piston engageable by the plunger as it travels in one direction in the cylinder, and means for limiting travel of the piston with the plunger in said one direction.

4. A pump according to claim 1 wherein the latch pin is reciprocable in a mounting member between its extended and retracted positons, and the other end portion of the latch pin projects from the mounting member so 4that the latch pin can be manually moved to retract it from the cylinder.

5. A pump according to claim `4 further comprising a bleed passage communicating with the cylinder, and means `for opening and closing said bleed passage.

inlet passage to liquid `the latch pin mounting member against the latch pin,

and the pressure required to retract the said spring is less than the second check valve.

7. A pump according to `claim 1 wherein the plunger reciprocating means comprises an operating handle attached to the plunger.

8. A pump for -liquids comprising a cylinder having an inlet check valve and an outlet check valve, means for introducing liquid into the cylinder through said inlet check valve, a movable member mounted for `displacement into the cylinder and exposure to sucient pressure in the cylinder for displacement therefrom, means biasing said movable member toward the position in the cylinder, a piston reciprocable in the cylinder from a retracted positon on one side of the movable member wherein the advance of the piston for ejection of liquid from the cylinder may -be blocked by the movable member, said piston having a cylindrical passage therethrough, a plunger reciprocable in said passage and having a sliding seal with respect thereto, said plunger and piston having interengageable stop means providing for relative lost motion between relative positions in which the plunger reciprocates the piston between opposite sides of said movable member, oscillating means for reciprocating the plunger, whereby lost motion of the plunger relative to the piston when the piston is on said one side of the movable member forces the plunger into the cylinder substantially to raise the pressure of substantially gasfree liquid in the cylinder to force the movable means against its bias out of the cylinder, thereby to permit movement of the piston past the movable member for ejecting such substantially gas-free liquid from the cylinder, said means biasing the movable member into the cylinder with sufficient force to push the movable member into the cylinder against lower pressures engendered in substantially gas-entrained liquid by lost-motion movement of the plunger into the cylinder, thereby to block advance of the piston past the movable member when the cylinder contains liquid and a substantial `amount of gas.

9. A pump according to claim 8, including a manually operable relief port for the cylinder, and external manually operable means for retracting said movable means from the cylinder to permit the piston to move past the movable means for ejection of gas-entrained liquid through said relief port when manually opened.

10. A pump according to claim 9 wherein said outlet check valve is closed with sullicient force to prevent its opening in response to any pressures engendered by latch pin against the pressure required to unseat movement of the plunger into liquid in the cylinder whether or not gas is entrained therewith.

References Cited by the Examiner UNITED STATES PATENTS 1,718,985 7/ 1929 Scoville 222-383 2,027,500 1/ 1936 Vanderlip 222-383 2,425,867 8/1947- Davis Z22- 383 X 2,7 87,252 4/ 1957 Papanoli 92.--27 3,059,433 10/ 1962 Hirsch. `3,112,705 12/1963 Chlebowski 103-37 FOREIGN PATENTS 141,635 8/1949 Australia.

ROBERT B. REEVES, Primary Examiner. N. L. STACK, Assistant Examiner. 

1. A PUMP FOR LIQUIDS COMPRISING: A CYLINDER, A LIQUID INLET PASSAGE AND A LIQUID OUTLET PASSAGE COMMUNICATING WITH THE CYLINDER, A FIRST CHECK VALVE CLOSING THE INLET PASSAGE TO LIQUID DISCHARGED FROM THE CYLINDER, A SECOND CHECK VALVE CLOSING THE OUTLET PASSAGE TO THE FLOW OF LIQUID FROM THE OUTLET PASSAGE INTO THE CYLINDER, A PLUNGER, MEANS FOR RECIPROCATING THE PLUNGER THROUGHOUT A FULL STROKE, MEANS FOR LIMITING THE STROKE OF THE PLUNGER, A RECIPROCATING PISTON MOVABLE THROUGH THE CYLINDER BETWEEN A FIRST POSITION WHEREIN THE CYLINDER IS CHARGED WITH LIQUID AND A SECOND POSITION WHEREIN LIQUID HAS BEEN DISCHARGED FROM THE CYLINDER, THE PLUNGER HAVING A SLIDING LOST-MOTION CONNECTION WITH THE PISTON WHEREBY THE PLUNGER IS MOVABLE INTO THE CYLINDER RELATIVE TO THE PISTON DURING THE FIRST PART OF A CYLINDER DISCHARGING STROKE AND MOVABLE OUT OF THE CYLINDER RELATIVE TO THE PISTON DURING THE FIRST PART OF A CYLINDER CHARGING STROKE, AND A LATCH PIN HAVING AN END PORTION MOVABLE BETWEEN AN EXTENDED POSITION WHEREIN IT PROJECTS INTO THE CYLINDER ADJACENT TO THE PISTON WHEN THE PISTON IS IN ITS FIRST POSITION FOR BLOCKING MOVEMENT OF THE PISTON INTO THE CYLINDER AND A RETRACTED POSITION WHEREIN IT IS WITHDRAWN FROM THE CYLINDER TO PERMIT MOVEMENT OF THE PISTON FROM ITS FIRST POSITION TO ITS SECOND POSITION, MEANS BIASING THE LATCH PIN TO ITS EXTENDED POSITION, THE LATCH PIN BEING MOVED AGAINST THE BIASING MEANS TO ITS RETRACTED POSITION BY AN INCREASE IN PRESSURE OF SUBSTANTIALLY GAS-FREE LIQUID IN THE CYLINDER RESULTING FROM INITIAL MOVEMENT OF THE PLUNGER INTO THE CYLINDER DURING A CYLINDER DISCHARGING STROKE, THEREBY UNBLOCKING THE PISTON SO THAT FURTHER MOVEMENT OF THE PLUNGER AFTER ITS INITIAL LOST-MOTION TRAVEL RELATIVE TO THE PISTON CAUSES THE PISTON AND PLUNGER SIMULTANEOUSLY TO SWEEP THROUGH THE CYLINDER FOR DISCHARGING LIQUID FROM THE CYLINDER THROUGH THE OUTLET PASSAGE. 